leu·​cism | \ ˈlü-ˌsi-zəm How to pronounce leucism (audio) \

Definition of leucism

: an abnormal condition of reduced pigmentation affecting various animals (such as birds, mammals, and reptiles) that is marked by overall pale color or patches of reduced coloring and is caused by a genetic mutation which inhibits melanin and other pigments from being deposited in feathers, hair, or skin

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Other Words from leucism

leucistic \ lü-​ˈsi-​stik How to pronounce leucistic (audio) \ adjective

Examples of leucism in a Sentence

Recent Examples on the Web

The ghost lobster’s look is likely due to a genetic condition called leucism, which causes a partial loss of pigmentation in an animal, resulting in white, pale and patchy coloration. Alexandra Deabler, Fox News, "Maine fisherman catches rare 'ghost lobster'," 30 Aug. 2018 Most animals feature a range of color variations, including albinism (an absence of pigment) and leucism (a partial loss of pigmentation). Paul A. Smith, Milwaukee Journal Sentinel, "Wisconsin man encounters rare white deer fawn on Sauk County morel mushroom hunt," 15 May 2018 The white giraffes displayed the characteristics of a genetic condition known as leucism, which inhibits pigmentation in skin cells, Dr. Ali said. Yonette Joseph, New York Times, "Rare White Giraffes Cause a Stir in Kenya," 16 Sep. 2017 The giraffes' white color is caused by a genetic condition called leucism that affects their cells' pigmentation, the Program said. Rachel Lewis, Time, "Wildlife Experts Spotted a Rare All-White Giraffe and Her Cub in the Wild," 18 Sep. 2017 Animals with leucism may have darker pigment in their soft tissue, and their eyes retain a normal color. Yonette Joseph, New York Times, "Rare White Giraffes Cause a Stir in Kenya," 16 Sep. 2017 Despite their inability to produce colorful pigment, giraffes and other animals with leucism don’t face genetic disadvantages to their survival, but their color can attract unwanted attention. National Geographic, "Why These Giraffes Are Completely White," 14 Sep. 2017 Life can be tough for white squirrels, and other animals with leucism. Joan Morris, The Mercury News, "Unusual white squirrel seen cavorting in Walnut Creek," 11 Apr. 2017 There are three ways this can occur: albinism, leucism, and isabellinism. National Geographic, "Pictures: Rare White Giraffe and Other Unusually Pale Animals," 28 Jan. 2016

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'leucism.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of leucism

1878, in the meaning defined above

History and Etymology for leucism

borrowed from German Leucismus, from Greek leukós "clear, white" + German -ismus -ism — more at light entry 1

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Time Traveler for leucism

The first known use of leucism was in 1878

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an act or instance of returning to life

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